1 import time
2
3 # 2种表示时间的方法：
4 # (1)时间戳，从1970.1.1开始
5 # (2)一个9个整数的元组
6 # 这个元组内容：
7 # year (including century, e.g. 1998)
8 # month (1-12)
9 # day (1-31)
10 # hours (0-23)
11 # minutes (0-59)
12 # seconds (0-59)
13 # weekday (0-6, Monday is 0)
14 # Julian day (day in the year, 1-366)
15 # DST (Daylight Savings Time) flag (-1, 0 or 1)
16 # 1 if summer time is in effect, 0 if not, and -1 if unknown
17
18
19 # FUNCTIONS
20 """
21 time(...)
22 time() -> floating point number
23
24 Return the current time in seconds since the Epoch.
25 Fractions of a second may be present if the system clock provides them.
26 本地的当前时间的时间戳
27 """
28 print(time.time())
29
30 """
31 localtime(...)
32 localtime([seconds]) -> (tm_year,tm_mon,tm_mday,tm_hour,tm_min,
33 tm_sec,tm_wday,tm_yday,tm_isdst)
34
35 Convert seconds since the Epoch to a time tuple expressing local time.
36 When 'seconds' is not passed in, convert the current time instead.
37 没有参数时本地的当前时间的元组形式
38 """
39 print(time.localtime())
40
41 """
42 gmtime(...)
43 gmtime([seconds]) -> (tm_year, tm_mon, tm_mday, tm_hour, tm_min,
44 tm_sec, tm_wday, tm_yday, tm_isdst)
45
46 Convert seconds since the Epoch to a time tuple expressing UTC (a.k.a.
47 GMT). When 'seconds' is not passed in, convert the current time instead.
48
49 If the platform supports the tm_gmtoff and tm_zone, they are available as
50 attributes only.
51 """
52 print(time.gmtime(time.time()))
53
54
55 """
56 mktime(...)
57 mktime(tuple) -> floating point number
58
59 Convert a time tuple in local time to seconds since the Epoch.
60 Note that mktime(gmtime(0)) will not generally return zero for most
61 time zones; instead the returned value will either be equal to that
62 of the timezone or altzone attributes on the time module.
63 """
64 print(time.mktime(time.localtime()))
65
66
67 """
68 asctime(...)
69 asctime([tuple]) -> string
70
71 Convert a time tuple to a string, e.g. 'Sat Jun 06 16:26:11 1998'.
72 When the time tuple is not present, current time as returned by localtime()
73 is used.
74 tuple转字符串，默认是当前时间
75 """
76 print(time.asctime()) # Thu Jan 18 16:36:07 2018
77
78 """
79 ctime(...)
80 ctime(seconds) -> string
81
82 Convert a time in seconds since the Epoch to a string in local time.
83 This is equivalent to asctime(localtime(seconds)). When the time tuple is
84 not present, current time as returned by localtime() is used.
85 时间戳转字符串，默认是当前时间
86 """
87 print(time.ctime())
88
89 """
90 strftime(...)
91 strftime(format[, tuple]) -> string
92
93 Convert a time tuple to a string according to a format specification.
94 See the library reference manual for formatting codes. When the time tuple
95 is not present, current time as returned by localtime() is used.
96
97 Commonly used format codes:
98
99 %Y Year with century as a decimal number.
100 %m Month as a decimal number [01,12].
101 %d Day of the month as a decimal number [01,31].
102 %H Hour (24-hour clock) as a decimal number [00,23].
103 %M Minute as a decimal number [00,59].
104 %S Second as a decimal number [00,61].
105 %z Time zone offset from UTC. +0800
106 %a Locale's abbreviated weekday name. Thu
107 %A Locale's full weekday name. Thursday
108 %b Locale's abbreviated month name. Jan
109 %B Locale's full month name. January
110 %c Locale's appropriate date and time representation. Thu Jan 18 16:53:35 2018
111 %I Hour (12-hour clock) as a decimal number [01,12]. 04
112 %p Locale's equivalent of either AM or PM. PM
113
114 Other codes may be available on your platform. See documentation for
115 the C library strftime function.
116 格式化元组到字符串
117 """
118 print(time.strftime('%Y-%m-%d %H:%M:%S', time.localtime()))
119
120 """
121 strptime(...)
122 strptime(string, format) -> struct_time
123
124 Parse a string to a time tuple according to a format specification.
125 See the library reference manual for formatting codes (same as
126 strftime()).
127
128 Commonly used format codes:
129
130 %Y Year with century as a decimal number.
131 %m Month as a decimal number [01,12].
132 %d Day of the month as a decimal number [01,31].
133 %H Hour (24-hour clock) as a decimal number [00,23].
134 %M Minute as a decimal number [00,59].
135 %S Second as a decimal number [00,61].
136 %z Time zone offset from UTC.
137 %a Locale's abbreviated weekday name.
138 %A Locale's full weekday name.
139 %b Locale's abbreviated month name.
140 %B Locale's full month name.
141 %c Locale's appropriate date and time representation.
142 %I Hour (12-hour clock) as a decimal number [01,12].
143 %p Locale's equivalent of either AM or PM.
144
145 Other codes may be available on your platform. See documentation for
146 the C library strftime function.
147 字符串到元组
148 """
149 #
150 print(time.strptime('2018-01-18 16:55:01', '%Y-%m-%d %H:%M:%S'))
151 print(time.strptime('Thu Jan 18 16:55:56 2018', '%c'))
152
153 """
154 sleep(...)
155 sleep(seconds)
156
157 Delay execution for a given number of seconds. The argument may be
158 a floating point number for subsecond precision.
159 """
160 """
161 clock(...)
162 clock() -> floating point number
163
164 Return the CPU time or real time since the start of the process or since
165 the first call to clock(). This has as much precision as the system
166 records.
167 """
168 def func():
169 sum = 0
170 for i in range(1000):
171 sum = sum + 1
172 time.sleep(0.01)
173
174 t0 = time.clock()
175 p0 = time.time()
176 print(t0, p0)
177 func()
178 t1 = time.clock()
179 p1 = time.time()
180 print(t1, p1)
181 print(t1-t0, p1-p0) # 0.08869099999999999 10.986821174621582
182 # linux端，clock只统计cpu运行的时间，执行语句，sleep不统计。windows不一样
183
184 """
185 get_clock_info(...)
186 get_clock_info(name: str) -> dict
187
188 Get information of the specified clock.
189 """
190 print(time.get_clock_info('clock'))
191 print(time.get_clock_info('monotonic'))
192 print(time.get_clock_info('perf_counter'))
193 print(time.get_clock_info('process_time'))
194 print(time.get_clock_info('time'))
195
196
197 """
198 monotonic(...)
199 monotonic() -> float
200
201 Monotonic clock, cannot go backward.
202 系统启动，开启的一个时钟，也就是系统开启时间
203 """
204
205
206 """
207 perf_counter(...)
208 perf_counter() -> float
209
210 Performance counter for benchmarking.
211 系统运行时间
212 """
213
214
215 """
216 process_time(...)
217 process_time() -> float
218
219 Process time for profiling: sum of the kernel and user-space CPU time.
220 """
221 def func():
222 sum = 0
223 for i in range(1000):
224 sum = sum + 1
225 time.sleep(0.01)
226
227 t0 = time.process_time()
228 p0 = time.time()
229 print(t0, p0)
230 func()
231 t1 = time.process_time()
232 p1 = time.time()
233 print(t1, p1)
234 print(t1-t0, p1-p0) # 0.08869099999999999 10.986821174621582
235 # 统计内核和用户空间占用cpu的时间
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